How did you manage to get an RI on a mounted stone? I would take the stone out of the setting and recheck the RI and study the inclusions. According the R. Webster, natural alexandrite shows a weak red glow under both long and short UV. And yes, it should turn red in a Chelsea filter because of the chromium content. However, I don’t think fluorescence or a chrome filter will give you a conclusive identification because synthetic alexandrite probably reacts the similarly. Anyway, there are several manufacturers of synthetic alexandrite and their UV reactions will vary.
As far as I know UV light reactions are not at all useful to differentiate between natural and synthetic alexandrite. You really need to look at the inclusions or send the stone to a competent lab.

I have Alexandrite Peices which are rough (raw) and they are 2 to 7 carat in size. I would be glad to know if I can get information regarding it and where do I sell it in India and Whom to contact. Alexandrite are color changing.

We have an old ring that is approximately 3-4 carets, round cut set in 18c gold. The jeweler we took it to told us it was an alexandrite. The color changes from dark purple to deep green. I am not sure if it is a genuine natural stone or lab created - my guess would be lab or simulated since it is so large. Can you give me an idea on the approximate value of this stone/ring ?

Chrysoberyl is the species name and Alexandrite is the variety name. Alexandrite is that variety of chrysoberyl that changes color as a function of the light source; green in daylight and red under incandescent light.

The mining of alexandrite in Russia lasted less than 100 years from the time it was discovered in 1833 to the early 1900’s. It was George Kunz, the gemologist/gemstone buyer for Tiffany & Co that probably did the most to popularize this unique gemst

Russian Alexandrites is illustrated with more than 200 colour figures and photographs, addresses mineralogists, gemmologists, historians, mineral and gem collectors as well as all members of the gem trade.

Russian Alexandrites is illustrated with more than 200 colour figures and photographs, addresses mineralogists, gemmologists, historians, mineral and gem collectors as well as all members of the gem trade.

The retail replacement cost for a 1ct. alexandrite could be anywhere between $500 to $12,000 per carat. The intensity of the color change and the attractiveness of the colors are the most important factors in determining the value of an alexandrite. With

Along with diamonds, rubies, and emeralds, top quality alexandrites are among the most expensive gemstones in the world. In larger sizes over 4.00 or 5.00cts., Burmese rubies are more rare and expensive than alexandrites but in sizes below 1.00cts., alexa